Multi-center study for the utilization of quality of life questionnaire for adult Korean asthmatics (QLQAKA)

Abstract

Background and objective：Assessment of quality of life (QOL) of patients with chronic illness requires reasonable tools which reflect the patients' cultural and behavioral properties. We developed the quality of life questionnaire for adult Korean asthmatics (QLQAKA) on the basis of the Korean life style and evaluated its reliability and validity. Methods：The QLQAKA consisted of four domains; symptoms (six items), daily activity (five items), emotion (three items) and reaction to environmental stimuli (three items). Patients answered each item according to a five-response scale. The reproducibility and validity of the questionnaire was estimated from the responses of 244 patients who visited the clinics in 15 institutes within a 2-week interval. Results：Items with the most frequent complaints were dyspnea (87%), difficulty in sputum discharge or throat clearing (87%), limitation in strenuous activity (84%) and coughing (82.4%). The QLQAKA reflected the changes of patients' status very well. The value of minimal important differences, such as the clinically significant minimal change in the QOL score, was 0.5. The questionnaire was also highly reproducible with the value of intraclass correlation coeffi- ciency and intraclass standard deviation as 0.940 (p<0.001) and 0.180, respectively. The changes of mean total QLQAKA score correlated weakly with the changes of FEV1 and PEFR values. Conclusion：The adult version of QLQAKA was valid and may be a reproducible tool for evaluating and monitoring Korean adult asthma patients.